Ball Bearings 2x5x2.3 Stainless Steel Lot of 10 Bearings 10 Bearings Stainless Steel Ball Bearings , this is a popular size that could be used in many application that uses this size 2mm x 5mm x 2.3mm. Bearings are made of Stainless Steel and can rotate up to 80,000 rpm, each bearing are rubber sealed from both sides to protect the bearing from dust or any possible contamination, also bearings are pre-lubricated with grease.